Swim means nothing in Spanish. In Spanish, the verb "to swim" is "nadar."
swimming
It means "swimming," referring to the sport/practice itself, not the verb.
A man is swimming in the pool.
It means swimming. It the gerund (present participle) form of the verb: to swim.
natación This is 'swimming' the noun, not 'swimming' the participle. 'Swimming' the participle is nadando. To say, "The swimming team is swimming." in Spanish, you say, "El equipo de natación está nadando."
swimming is nadar and walking in camina
To swim or swimming in spanish nadar.
swimming pool = alberca (ahl-BER-kah). Some people use the word piscina, but piscina is more of a (fish) pond than a swimming pool.
Nadar- to swim
nadar
They swim/they are swimming
Tu nadas EN la pisCina = you swim in the fishpond/swimming-pool